Shark Man resides deep in the ocean and requires those who seek to do battle with him to swim through hordes of enemies in order to find him. He is very mobile in the water and uses his signature Shark Boomerang to take out opponents at a great distance. However, Shark Man is weak against Oil Man's Oil Stream weapon.
Mega Man 3 PC/DOS - Shark Man Stage
Shark Man's mugshot is an edited version of Snake Man's mugshot, while his general appearance is a hybrid of Snake Man and Gemini Man.
Shark Man's mugshot shows a face inside his shark mouth, but his sprite seems to have the face shrouded in a shadow from his helmet.
Shark Man's weakness to Oil Stream is probably a reference to oil spills.